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Subject: FW: [vintagesynthrepair] oscillator calibration (general)

From: "Verschut, Ricardo" <ricardo.verschut@...>
Date: 2002-03-18

-----Original Message-----
From: Robert Williams [mailto:will7370@...]
Sent: Monday, March 18, 2002 4:34 PM
Subject: Re: [vintagesynthrepair] oscillator calibration (general)

Isn't it a known fact that to get a musically useful tuning you cannot
go by a perfect mathmatical tuning? Seems to me I remember that if you
tune "by the numbers" on a freq counter you will get odd harmonics and
beating. But if you tune "by ear" you will find that the numbers aren't
exact on the freq counter, but it will be far more musically useful.

If anyone knows of a web page where this is documented fully, let us
know. I'd be interested in seeing the math.


>>> tom@... 03/18/02 07:13 AM >>>
Normally I calibrate a synth using my Boss TU-12H tuner which works
over a wide range and is very portable. However, this weekend I
was calibrating a Jupiter-8 and discovered something. After going
it with the tuner, I powered it up and started playing some widely
chords to hear the oscillator interaction. The beating was very

I decided to use my scope and tune by the Lissijous (sp?) method. I
created a 220, 440, 880, and 1760 sine waves in Cool Edit and ran the
output into one scope trace and the synth output into the other.

The end result was that I tuned the synth faster and it sounded better
using that method. Since the JP-8 is not necessarily the most precise
instrument across all the octaves, there was still some beating, but it
was more 'musical' sounding. Unless I started replacing components, I
don't think I can eliminate all beating across 16 VCOs across 8 octaves.

What do you guys use for tuning? Anyone using a strobe tuner? How does
that compare for 'real world' sound and speed?

Tom Moravansky tom@...

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